VSAT means Very Small Aperture Terminal, which in plain English means a two-way satellite Internet antenna that is less than 3 meters in diameter. Any earth-based satellite antenna larger than that is considered an Earth Station. VSATs come in all sizes and shapes, most are curved so that they concentrate reflected Radio Frequency (RF) into a more narrowly focused area where it can be most easily received by the antenna's electronics. VSATs can be installed on buildings, boats, vehicles, trains, planes, or ground mounted.